Fauna
Plant

Narrowleaf Sword Fern

Polystichum imbricans

Also known as Imbricate Sword Fern, Narrowleaf Swordfern

Narrowleaf sword ferns form tidy, upright tufts of leathery, evergreen fronds that thrive in dry, rocky terrain where other ferns struggle. Their narrow, densely clustered pinnae overlap like roof shingles, an adaptation that minimizes moisture loss in sun-exposed rock cracks. These hardy perennials play an important role in stabilizing talus slopes and cliff faces across western mountain ranges.

EvergreenFernDrought-Tolerant
Narrowleaf Sword Fern reference1 / 7
(c) Ed Alverson, some rights reserved (CC BY) · cc-by
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Least ConcernConservation statusIUCN Red List categoriesLCNTVUENCREWEXLeast ConcernRed List categories, explained →
Key facts
Diet & preyAutotrophic (Photosynthesis)
Predators
  • Browsing deer
  • Herbivorous insects
  • Slugs
ThreatsHabitat disturbance, altered fire regimes, invasive weed encroachment
HabitatsRocky outcrops, talus slopes, dry forest openings, cliff crevices
Life spanPerennial (decades)
Classification
  1. FamilyDryopteridaceae
  2. SpeciesPolystichum imbricans
Range & activity
Range data is not available yet.
Safe observation
Interaction riskLow
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is low
Safe to observe at a normal distance.
Responsible observation
  • Spotting: Look for overlapping, stiff pinnae growing directly out of rock crevices.
  • Habitat: Search dry, exposed rocky slopes where shade-loving ferns cannot survive.
  • Photography: Capture the pale brown scales along the lower leaf stem for key ID details.
Related species
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